The Four Largest Islands of Japan | USA Today The Four Largest Islands of Japan Osaka, in Honshu, circa 1830 (Photo: Photos.com/Photos.com/Getty Images ) How to Go to Japan for Vacation The Japanese archipelago consists of thousands of islands, but the Japan of world maps -- the bow-shaped country in the Pacific curling around the east coast of continental Asia -- is made up of four main islands: Hokkaido, Honshu, Kyushu and Shikoku. Honshu is the largest, roughly the size of Minnesota, followed by Hokkaido, Kyushu and Shikoku. Each island offers something a little different for the tourist, but the four are unified by Japan's technology and hospitality. Honshu When you look at a map of Japan, you can see the divides between its four main land masses. Honshu is central, with Tokyo in the central part of the island. The main island is also home Osaka, Kobe, Kyoto and Nagoya, and the majority of Japan's population lives here. Most international flights to Japan arrive through Tokyo or Osaka, so Honshu is the most frequently visited island, partly by default.

Its large cities take some getting used to for the traveler, but with great reward. Starting a Honshu trip in Osaka makes sense, as Kobe, Kyoto and the spectacular Nara are only an hour away by train, some high-speed, some commuter. All major cities in Honshu are connected by rail, though flying on the longer trips -- Hiroshima to Tokyo, for example -- might be more economical. Hokkaido Hokkaido is the dot on the Japanese "j," the second-largest and northernmost island. Hokkaido's largest city is Sapporo, where the well known Japanese beer of the same name comes from, and most Hokkaido vacations begin here. The island is known for its natural landscape, with an abundance of national parks and festivals celebrating its earthly beauty. Hokkaido's Winter Festival brings visitors from around the world and around Japan to the region each year, and the Hokkaido's mountains draw skiers and snowboarders to their deep, pristine powder. Kyushu Kyushu is Japan's third-largest island and the southernmost of the main four.

Despite being separated by a small gulf from Honshu, Kyushu is well-connected by rail and bus service to Honshu. Kyushu's largest city is Fukuoka, the fourth-largest city in Japan, an industrial metropolis on the northern edge of Kyushu. While Fukuoka is the central hub of the island, it's by no means the most interesting city. Nagasaki is smaller, but quaint, with old stone streets, trolleys, shopping and museums. Kumamoto, two hours south of Fukuoka, is an old fortress city, with one of Japan's oldest and best-maintained feudal castles and walls evoking the Japan of the nation's nightly historical dramas. Shikoku The smallest of Japan's four main islands, Shikoku has a bit of a little-sibling complex. It doesn't boast mountains as big as those in northern Honshu or Hokkaido, and it doesn't have the same near-tropical climate as southern Kyushu. So Shikoku is modest, offering tourists a tamer version of the busier tourist regions of Japan.

Its natural scenery is its key draw, with smallish mountains under 6,000 feet that appeal to outdoors enthusiasts in moderate physical shape. Each year, Shikoku is home to a Buddhist pilgrimage, as pilgrims, mostly from around Japan, come to circumnavigate the island. In the past, pilgrims walked clockwise around the island and some disappeared forever in the mountainside forests; now, motorways and cell phones make disappearing almost impossible, but the festival remains strongly rooted in the Shikoku consciousness. References Overview of the Four Islands of Japan • Honshu Honshu is the largest island of Japan and it is where the majority of the country's cities are located ( maps ). The Tokyo Osaka-Kyoto area is the core Honshu and Japan and 25% of the island's population lives in the Tokyo region. Honshu has a total area of 88,017 square miles (227,962 sq km) and it is the world's seventh largest island. The island is 810 miles (1,300 km) long and it has a varied topography that includes many different mountain ranges, some of which are volcanic.

The highest of these is the volcanic Mount Fuji at 12,388 feet (3,776 m). Like many areas of Japan, earthquakes are also common on Honshu. Honshu is divided into five regions and 34 prefectures . The regions are Tohoku, Kanto, Chubu, Kansai and Chugoku. More » continue reading below our video 10 Facts About the Titanic That You Don't Know • Hokkaido Hokkaido is the second largest island of Japan with a total area of 32,221 square miles (83,453 sq km). The population of Hokkaido is 5,507,456 (October 2010 estimate) and the main city on the island is Sapporo, which is also the capital of Hokkaido Prefecture. Hokkaido is located to the north of Honshu and the two islands are separated by the Tsugaru Strait ( map ). The topography of Hokkaido consists of a mountainous volcanic plateau in its center that is surrounded by coastal plains.

There are a number of active volcanoes on Hokkaido, the tallest of which is Asahidake at 7,510 feet (2,290 m). Since Hokkaido is located in northern Japan, it is known for its cold climate. Summers on the island are cool, while winters are snowy and icy. More » • Kyushu Kyushu is the third largest island of Japan and it is located to the south of Honshu ( map ). It has a total area of 13,761 square miles (35,640 sq km) and a 2006 population of 13,231,995 people. The largest city on Kyushu is Fukuoka and it is divided into seven prefectures. Kyushu's topography consists mainly of mountains and the most active volcano in Japan, Mt. Aso, is located on the island. In addition to Mt. Aso, there are also hot springs on Kyushu and the highest point on the island, Kuju-san at 5,866 feet (1,788 m) is also a volcano.

Since it is in southern Japan, Kyushu has a subtropical climate and its inhabitants produce a variety of agricultural products. These include rice, tea, tobacco, sweet potatoes and soy. More » • Shikoku Shikoku is the smallest of Japan's main islands with a total area of 7,260 square miles (18,800 sq km). This area is made up of main island as well as the small islets surrounding it. It is located to the south of Honshu and to the east of Kyushu and has a population of 4,414,955 (2005 estimate) ( map ). The largest city of Shikoku is Matsuyama and the island is divided into four prefectures. Shikoku has a varied topography that consists of a mountainous south, while there are small lowland plains on the Pacific coast near Kochi. The highest point on Shikoku is Mount Ishizuchi at 6,503 feet (1,982 m). Like Kyushu, Shikoku has a subtropical climate and agriculture is practiced in its fertile coastal plains, while fruit is grown in the north.

More » What Are the Four Main Islands of Japan? By Matt Rosenberg Updated August 06, 2016. Japan's "mainland" consists of four primary islands: Hokkaido, Honshu, Kyushu, and Shikoku. In total, the country of Japan includes 6,852 islands, many of which are very small and uninhabited. When trying to remember where the major islands are located, you can think of the archipelago of Japan as a letter "j." Hokkaido is the j's dot. Honshu is the long body of the j. Shikoku and Kyushu make up the j's sweeping curve. The Island of Honshu Honshu is the largest island and the core of Japan. It is also the seventh largest island in the world. On the island of Honshu, you will find the majority of the Japanese population and most of its major cities including the capital of Tokyo. Because it is the center of Japan, Honshu is connected to the other primary islands via undersea tunnels and bridges.

Roughly the size of the state of Minnesota, Honshu is a mountainous island and home to many of the country's active volcanoes. Its most famous peak is Mt. Fuji. Major Cities: Tokyo, Hiroshima, Osaka-Kyoto, Nagoya, Sendai, Yokohama, Niigata Key Mountains: Mount Fuji (Japan's highest point at 12,388 feet/3776 meters), Mount Kita, Mount Hotaka, Hilda Mountains, Ou Mountains, Chugoku Range Other Key Geographic Features: Lake Biwa (Japan's largest lake), Mutsu Bay, Inawashiro Lake, Tokyo Bay The Island of Hokkaido Hokkaido is in the northernmost and second largest of the main Japanese islands. It is separated from Honshu by the Tsugaru Strait. Sapporo is the largest city on Hokkaido and also serves as the island's capital. The climate of Hokkaido is distinctly northern. It is known for its mountainous landscape, a number of volcanoes, and natural beauty.

It is a popular destination for skiers and outdoor adventure enthusiasts and Hokkaido is home to many national parks, including Shiretoko National Park. During the winter, drift ice from the Ohotsk Sea creeps toward the northern coast and this is a popular site starting in January. The island is also known for its many festivals, including the popular Winter Festival. Major Cities: Sapporo, Hakodate, Obihiro, Asahikawa, Obihiro, Kitami, Shari, Abashiri, Wakkanai Key Mountains: Mount Asahi (highest point on the island at 7516 feet/2291 meters), Mount Hakuun, Mount Akadake, Mount Tokachi (active volcano), Daisetsu- zan Mountains Other Key Geographic Features: Sounkyo Gorge, Lake Kussharo, Lake Shikotsu The Island of Kyushu The third largest of Japan's big islands, Kyushu is to the southwest of Honchu. The largest city is Fukuoka and this island is known for its semi-tropical climate, hot springs, and volcanoes.

Kyushu is known as the "Land of Fire" because of its chain of active volcanoes, which include Mount Kuju and Mount Aso. Major Cities: Fukuoka, Nagasaki, Kagoshima Key Mountains: Mount Aso (active volcano), Mount Kuju, Mount Tsurumi, Mount Kirishima, Sakura-jima, Ibusuki Other Key Geographic Features: Kumagawa River (largest on Kyushu), Ebino Plateau, multiple small islands The Island of Shikoku Shikoku is the smallest of the four islands and is located to the east of Kyushu and southeast of Honshu. It is a picturesque and cultural island, boasting many Buddhist temples and the home of famous haiku poets. Also a mountainous island, Shikoku's mountains are small in comparison to others in Japan as none of the island's peaks is higher than 6000 feet (1828 meters). There are no volcanoes on Shikoku. Shikoku is home to a Buddhist pilgrimage that is known worldwide. Visitors can walk around the island - either clockwise or counter-clockwise - visiting each of the 88 temples along the way.

It is one of the oldest pilgrimages in the world. Major Cities: Matsuyama, Kochi Key Mountains: Mount Sasagamine, Mount Higashi-Akaishi, Mount Miune, Mount Tsurugi Other Key Geographic Features: Inland Sea, Hiuchi-nada Sea, Bingonada Sea, Iyo-nada Sea The Largest Japanese Islands - WorldAtlas.com World Facts The Largest Japanese Islands Honshu, Japan's largest island, is also the seventh largest in the world, and home to the metropolis of Tokyo. Two different perspectives are depicted in these maps of the major islands of Japan. Japan is home to one of the most advanced and developed societies in the world . Japan has one of the highest life expectancies in the world and is home to one of the largest and most important cities worldwide, the metropolis of Tokyo. It is also one of the most homogeneous countries on the planet. Japan has five major islands that this article will discuss. They are Honshu, Hokkaido, Kyushu, Shikoku and Okinawa. Japan's Biggest Islands 5.

Okinawa (466 square miles) Okinawa is located between the East China Sea and the North Pacific Ocean, it is the largest and most populated on the 72 islands in the chain that make up the Ryukyu Archipelago . Okinawa is a subtropical island that has a average yearly temperature of around 68° Fahrenheit (20° Celsius). Among the prefectures of Japan, Okinawa actually has the youngest and fastest growing population, despite the fact that Okinawa's population is know as one of the oldest in the world. There are 34 centenarians (people over 100) per 100,000 people on the island. Okinawa has the lowest employment rate and average income compared to other prefectures and its economy is mainly driven by tourism and the United States military presence on the island, which is unpopular with Okinawa residents. Two of the major tourist attractions are the Okinawa Churaumi Aquarium and Hiji Falls National Park. Okinawa's capital city, Naha, is the biggest city on the island, accounting for almost 25% of Okinawa's population. 4.

Shikoku (7,300 square miles) Shikoku has a subtropical climate with short mild winters and long hot summers. It also has high mountains and steep slopes, which limit habitability. Shikoku is the smallest of the four main island in the Japanese Archipelago. The island has few natural resources or large scale industry, but it does produce extensive food, beverage, livestock and tobacco industries. It also produces many pulp, paper and chemical products. Shikoku is famous for its 88 temple pilgrimage associated with the priest Kūkai and the Obon festival. The largest city on the island is the capital of the Ehime Prefecture, Matsuyama. 3. Kyushu (13,760 square miles) Kyushu is a mountainous island, with many signs of tectonic activity, including numerous areas with hot springs and volcanoes. The island houses Japan's most active volcano, Mt. Aso. Major agriculture products the island produces are rice, tea and soy. The island also widely produces silk and is noted for various types of porcelain. Heavy industry is located in the northern part of the island, which includes chemical and metal processing.

The largest city on the island is Fukuoka, which is the capital city of Fukuoka Prefecture. Kyushu is also home to the city of Nagasaki, which was only the second and to date the last city on Earth to experience a nuclear attack . 2. Hokkaido (32,222 square miles) Hokkaido is the northernmost and largest prefecture in Japan. The island is know for its cool summers and cold winters. The center of the island has a large number of volcanic and mountains, while there are coastal plains in all directions outwards from this center. The island also has a number of National and Semi-national Parks. The island has some light industry, like beer brewing and paper milling, but most of the island's people work in the service sector. Hokkaido also has a major role in agriculture, ranking first in Japan in production on a number of products like corn, beef, and wheat. The tourism industry also plays an important role in the economy. The largest city on the island is the capital of the prefecture, Sapporo which is also the fourth largest city in Japan. 1.

Honshu (88,017 square miles) Honshu is the largest and most populous island in the Japanese archipelago and the seventh largest island in the world. The island is mountainous and volcanic, with the Japanese Alps run through the length of the island. Mt. Fuji is the highest mountain peak in Japan, an active volcano and one of the most well known mountains in the world. Honshu features many rivers, including the longest one in Japan the Shinano River. The island's climate is divided between humid subtropical in the south and humid continental in the north. Fruits, vegetables, rice, cotton, and the bulk of Japan's tea and silk all come from the island. The island has many diverse heavy industry jobs including, electronics, metallurgical, chemical and textile. Many of Japan's largest and most important cities are located on Honshu. There are populous major port and historical cities like Osaka, Kobe, Nagoya and Yokohama.

Hiroshima, the first city to experience the horrors of a nuclear bomb , is on Honshu, The former capital of Japan, Kyoto, and the current capital of Tokyo, one of the most populous and well know cities in the world, are also on the island. Japan and Its Varied Islands Now you know all about the various elements and differences between the biggest islands of Japan. It is very interesting to see the differences between each island's climate, geography, climate, and major cities. Each of Japan's islands clearly has a important role for the country, while having its own uniqueness as well. I hope that you are now more informed on Japan should you ever visit the magical "Land of the Rising Sun". The Biggest Islands Of Japan Rank Largest Islands of the World A map of the Largest Islands Greenland - (840,004 sq. miles) (2,175,600 sq. km) New Guinea - (303,381 sq. miles) (785,753 sq. km) Borneo - (288,869 sq. miles) (748,168 sq.

km) Madagascar - (226,917 sq. miles) (587,713 sq. km) Baffin - (194,574 sq. miles) (503,944 sq. km) Sumatra - (171,069 sq. miles) (443,066 sq. km) Honshu - (88,982 sq. miles) (225,800 sq. km) Great Britain - (88,787 sq. miles) (229,957 sq. km) Victoria - (85,154 sq. miles) (220,548 sq. km) Ellesmere - (71,029 sq. miles) (183,965 sq. km) NOTE: Australia is widely considered as a continental landmass, not an island. It certainly is the largest island, with a size of (2,941,517 sq miles) (7,618,493 sq km).

LARGEST ISLAND COUNTRIES Indonesia - (735,358 sq miles) (1,904,569 sq km) Madagascar - (226,917 sq miles) (587,713 sq km) Papua New Guinea - (178,704 sq miles) (462,840 sq km) Japan - (143,939 sq miles) (372,801 sq km) Malaysia - (127,320 sq miles) (329,758 sq km) Philippines - (115,831 sq miles) (300,000 sq km) New Zealand - (103,883 sq miles) (269,057 sq km) Great Britain - (88,787 sq miles) (229,957 sq km) NOTE: Great Britain is an island that combines the countries of England, Scotland, and Wales, and is a part of the country of the "United Kingdom of Great Britain and Northern Ireland," commonly referred to as the UK.

Cuba - (42,804 sq miles) (110,861 sq km) Iceland - (39,769 sq miles) (103,000 sq km) HIGHEST ISLANDS New Guinea - (16,503 feet) (5,030 meters) Hawaii, USA - (13,796 feet) (4,205 meters) Borneo, Indonesia - (13,698 feet) (4,175 meters) Formosa, China - (13,114 feet) (3,997 meters) Sumatra, Indonesia - (12,484 feet) (3,805 meters) Ross, Antarctica - (12,448 feet) (3,794 meters) Honshu, Japan - (12,388 feet) (3,776 meters) South Island, NZ - (12,349 feet) (3,764 meters) Lombok, Indonesia - (12,224 feet) (3,726 meters) LARGEST VOLCANIC IS

LANDS Sumatra, Indonesia - (171,069 sq miles) (443,066 sq km) Honshu, Japan - (87,182 sq miles) (225,800 sq km) Java, Indonesia - (53,589 sq miles) (138,794 sq km) North Island, NZ - (43,082 sq miles) (111,583 sq km) Luzon, Philippines - (42,458 sq miles) (109,965 sq km) Iceland - (39,769 sq miles) (103,000 sq km) Mindanao, Philippines - (37,657 sq miles) (97,530 sq km) Hokkaido, Japan - (30,395 sq miles) (78,719 sq km) New Britain, PNG - (13,569 sq miles) (35,145 sq km) Halmaherea, Indonesia - (6,965 sq miles) (18,04

0 sq km) LARGEST LAKE ISLANDS Manitoulin, Lake Huron - (1,068 sq miles) (2,766 sq km) Vozrozhdeniya, Aral Sea - (888 sq miles) (2,300 sq km) Rene-Lavasseur, Manicouagan Reservoir, Quebec, Canada - (780 sq miles) (2,000 sq km) Olkhon, Lake Baykal - (282 sq miles) (730 sq km) Samosir, Toba - (243 sq miles) (630 sq km) Isle Royal, Lake Superior - (209 sq miles) (541 sq km) Ukerewe, Lake Victoria - (205 sq miles) (530 sq km) St.

Joseph, Lake Huron - (141 sq miles) (365 sq km) Drummond, Lake Huron - (134 sq miles) (347 sq km) Idjwi, Lake Kivu, DRC - (110 sq miles) (285 sq km) LARGEST ISLANDS in the USA Hawaii, Hawaii - (4,037 sq miles) (10,456 sq km) Kodiak, Alaska - (3,672 sq miles) (9,510 sq km) Prince of Wales, Alaska - (2,587 sq miles) (6,700 sq km) Chichagof, Alaska - (2,085 sq miles) (5,400 sq km) Saint Lawrence, Alaska - (1,710 sq miles) (4,430 sq km) Admiralty, Alaska - (1,649 sq miles) (4,270 sq km) Baranof, Alaska - (1,636 sq miles) (4,237 sq km) Nunivak, Alaska - (1,625 sq miles)

 (4,210 sq km) Unimak, Alaska - (1,606 sq miles) (4,160 sq km) Long Island, NY - (1,401 sq miles) (3,629 sq km) LARGEST ISLANDS in EUROPE Great Britain - (88,787 sq miles) (229,957 sq km) Iceland - (39,769 sq miles) (103,000 sq km) Ireland - (33,342 sq miles) (83,766 sq km) West Spitsbergen - (15,200 sq miles) (39,368 sq km) Sicily - (9,807 sq miles) (25,400 sq km) Sardinia - (9,189 sq miles) (23,800 sq km) North East Land - (5,792 sq miles) (15,000 sq km) Cyprus - (3,572 sq miles) (9,251 sq km) Corsica - (3,36

7 sq miles) (8,720 sq km) Crete - (3,189 sq miles) (8,260 sq km) Volcano Islands | archipelago, Japan | Britannica.com Volcano Islands Mariana Islands Volcano Islands, Japanese Kazan-rettō, archipelago, Tokyo to (metropolis), far southern Japan .

The islands lie in the western Pacific between the Bonin Islands (north) and the Mariana Islands (south). The three small volcanic islands are, in north–south sequence, Kita-Iō (San Alexander) Island, Iō Island (Iō-tō; conventionally, Iwo Jima), and Minami-Iō (San Augustino) Island. Unclaimed until the arrival of Japanese fishermen and sulfur miners in 1887, the islands were claimed formally by Japan in 1891. Iwo Jima is the largest island, with a large stretch of level land that was converted into a military airfield during World War II . It lies about 760 miles (1,220 km) south of Tokyo . The island was the scene of a bloody battle between Japanese and U.S. forces in 1945. Under the peace treaty with Japan, that nation retained residual sovereignty over the archipelago, but the United States administered the islands from 1951 to 1968, when they were returned to Japan. Its name was officially changed to Iō-tō in 2007.

Learn More in these related articles: Tokyo-Yokohama Metropolitan Area metropolitan complex—commonly called Greater Tokyo—along the northern and western shores of Tokyo Bay, on the Pacific coast of the island of Honshu, central Japan. At its centre is the metropolitan prefecture, or metropolis (to), of Tokyo, Japan’s capital and largest city.... Iwo Jima island that is part of the Volcano Islands archipelago, far southern Japan. The island has been widely known as Iwo Jima, its conventional name, since World War II (1939–45). However, Japan officially changed the name to its Japanese form, Iō-tō (Iō Island), in 2007. Volcano Islands - Student Encyclopedia (Ages 11 and up) A group of three small islands, the Volcano Islands (in Japanese, Kazan-retto) lie in the western Pacific Ocean between the Bonin Islands to the north and the Mariana Islands to the south. The Volcano Islands belong to Japan.

The three volcanic islands are, from north to south, Kita-Io (San Alexander) Island, Io Island (now Io-to; conventionally, Iwo Jima), and Minami-Io (San Augustino) Island. Unclaimed until the arrival of Japanese fishermen and sulfur miners in 1887, the islands were claimed formally by Japan in 1891. Article History Corrections? Updates? Help us improve this article! Contact our editors with your feedback. MEDIA FOR: You have successfully emailed this. Error when sending the email. Try again later. Edit Mode Submit Tips For Editing We welcome suggested improvements to any of our articles. You can make it easier for us to review and, hopefully, publish your contribution by keeping a few points in mind. Encyclopædia Britannica articles are written in a neutral objective tone for a general audience. You may find it helpful to search within the site to see how similar or related subjects are covered. Any text you add should be original, not copied from other sources. At the bottom of the article, feel free to list any sources that support your changes, so that we can fully understand their context.

(Internet URLs are the best.) Your contribution may be further edited by our staff, and its publication is subject to our final approval. Unfortunately, our editorial approach may not be able to accommodate all contributions. Submit Thank You for Your Contribution! Our editors will review what you've submitted, and if it meets our criteria, we'll add it to the article. Please note that our editors may make some formatting changes or correct spelling or grammatical errors, and may also contact you if any clarifications are needed. Uh Oh There was a problem with your submission. Please try again later. Close Date Published: February 05, 2009 URL: Access Date: January 19, 2017 Share Public Roads - World's Longest Suspension Bridge Opens in Japan , July/August 1998 - World's Longest Suspension Bridge Opens in Japan by James D. Cooper On April 5, 1998, 10 years after construction began, the ribbon was cut to open the world's longest suspension bridge, the Akashi Kaikyo Bridge in Japan.

Following a parade of the 1,500 invited guests (including this author) across the bridge, the Crown Prince and Princess of Japan officiated the formal ceremony. The Akashi Kaikyo Bridge, also known in Japan as the Pearl Bridge, has a record main span of 1,991 meters. By comparison, the bridge is 366 meters (almost ÃÂ¼ mile) longer than the previous record holder, the StoreBaelt (East Bridge) in Denmark, which was also opened in 1998. The Akashi Kaikyo Bridge is also 580 meters longer than the Humber Bridge in England, constructed in 1981; 692 meters longer than the longest suspension bridge in the United States, the Verrazano-Narrows Bridge in New York, built in 1964; and 710 meters longer than the Golden Gate Bridge in San Francisco, constructed in 1937. It cost an estimated 500 billion Japanese yen (U.S. $3.6 billion) to build the bridge. Construction began in 1988 and involved more than 100 contractors.

Background The Akashi Kaikyo suspension bridge forms one link in the Kobe-Naruto highway route, which connects the main island of Honshu and the southern island of Shikoku. This route is the eastern-most route of three north-south traffic routes approved in the 1969 comprehensive Japan national development plan to stimulate local commerce and to facilitate the industrial development of the region. A central route, which connects Kurasiki on Honshu Island with Sakaide on Shikoku Island, was completed in 1988. A third route further to the west, the Onomichi-Imabari Route, will connect the Hiroshima greater metropolitan area with the Matsuyama area when completed in 1999. The 81-kilometer-long Kobe-Naruto Route is marked by the construction of two major suspension bridges, including the world's longest - the Akashi Kaikyo Bridge. This bridge with a total length of four kilometers crosses the Akashi Straits, connecting the Kobe area of Honshu with Awaji Island, the sixth largest island in Japan.

About 1,400 ships per day traverse the 1,500-meter-wide main shipping lane through the Akashi Straits into the inland sea. A second major bridge on this route, the Ohnaruto suspension bridge, was completed in 1995 and connects Shikoku Island with the southern end of Awaji Island. This link of modern highways, interchanges, and bridges will greatly expand the economy of Awaji Island. Bridge Construction and Features The bridge was constructed in 110-meter-deep water with tidal currents of 4.5 meters per second. Wind speeds of 80 meters per second and a potential 8.5 Richter magnitude earthquake 150 kilometers from the site had to be considered by the bridge owners, the Honshu-Shikoku Bridge Authority. Geology of the bridge site includes layered alluvium and diluvium deposits over what is called the hard Akashi or Kobe layer. Granite protrudes at the Awaji anchorage. The main span was designed to be 1,990 meters with two side spans of 960 meters each.

The bridge roadway surface is constructed on top of a 14-meter-deep by 35.5-meter-wide truss girder system suspended from main cables passing over two steel towers that rise 298 meters above main sea level. A 65-meter clearance is maintained over the shipping lane. The 1.12-meter-diameter main cables were erected using full-length, prefabricated strands. Approximately 181,400 metric tons of steel were used in the superstructure, and 1.42 million cubic meters of concrete were used in the substructure. Anchorages measure 63 meters by 84 meters in plan and extend into the Kobe and granite layers at the site. This required special foundation construction technology. The Honshu anchorage had to be embedded 61 meters below sea level, and the anchorage excavation had to be performed in open air. Therefore, an 85-meter-diameter circular slurry wall, 2.2 meters thick, was constructed and subsequently used as a retaining wall. Excavation within the slurry wall was followed by the placement of roller-compacted concrete to complete anchorage foundation construction.

The Awaji anchorage foundation was constructed using steel pipes and earth anchors to support the surrounding soil. The excavated foundation was filled with specially designed flowing-mass concrete. Both anchorages were completed with the construction of a huge steel supporting frame used to anchor the main suspension cable strands. Main tower piers were constructed in the Akashi Strait. The tower-pier foundations were designed to transmit 181,400 metric tons of vertical force to bedrock, approximately 60 meters below the water surface. The foundation was constructed using a newly developed laying down caisson method. Steel caissons, 80 meters in diameter and 70 meters in height, were towed to the tower sites, submerged, and set on the pre-excavated seabed. Pier-foundation construction was completed with the placement of concrete. Next, the main steel towers were erected on the concrete piers. Each main-tower height is 282.8 meters (297.3 meters with cable saddle in place) and was erected by stacking 30 approximately 10-meter-high prefabricated steel segments on top of each other. The segments are formed with three separate cells in plan view.

Special procedures were used during fabrication of each segment to assure tight tolerances for proper tower alignment. The tolerances were maintained using laser measuring technologies for controlling all dimensions. The technology resulted in no major erection problems during field bolting and splicing together of the steel tower segments. An independent, self-supporting, 145-metric ton, tower crane was used during tower erection. Tuned mass dampers were attached to each tower at varying stages of completion to reduce wind-driven tower motion and reduce tower vibration in the event of an earthquake. Prior to stringing the cable, a pilot hauler rope was attached to each anchorage and placed over the tower tops by helicopter. The pilot rope was used to suspend the catwalk from which work on the main cable erection would proceed. The main cables, which have a 1-to-10 sag ratio, were erected using the prefabricated strand method. Cable strands, comprised of 127 5.23-millimeter-diameter galvanized wires, were factory-fabricated in 4,085-meter lengths.

High-strength wire with a tensile strength of 180 kilograms per square millimeter (kg/mm2) was used rather than the standard 160-kg/mm2 wire. Each strand was transported to the construction site where it was pulled from one anchorage over the saddle of each tower and fastened to the opposite anchorage frame. This procedure was repeated 289 times to fabricate each main cable. Each main cable was separated at the anchorage by a splay saddle prior to attachment to the steel frame inside the anchorage to equally distribute cable tension to the foundation. A specially designed cable-squeezing machine was used to compress the 290 parallel wire strands into the final 1.12-meter-diameter cable. Cable bands were placed to circumferentially compress the cable and to maintain the circular shape. Finally, suspender cable hangers were attached to the main cable to support the main stiffening truss. Hanger cables or ropes were factory-fabricated from bundled, 7-millimeter-diameter, 180-kg/mm2, parallel wire strands.

Because the higher strength wire was used, two (rather than the usual four) hanger ropes were required to support the panel points of the stiffening truss girders. Steel stiffening truss girder panels were fabricated off-site and transported by barge to the bridge tower piers, lifted to roadway elevation, and transported by traveler crane to the proper location for connection to the suspender ropes. This procedure allowed the uninterrupted use of the busy shipping lane of the Akashi Straits. Several unique technologies were developed to support the design and construction of the Akashi Kaikyo suspension bridge. The aerodynamic stability of long suspension bridges poses major challenges to designers. To verify the design of the world's longest suspension bridge, the Honshu-Shikoku Bridge Authority contracted with the Public Works Research Institute to construct the world's largest wind-tunnel facility and to test full-section models in laminar and turbulent wind flow. Other innovations resulting from wind-tunnel testing included installation of vertical plates at the bottom center of the highway deck to increase flutter speed. Methods of improved prediction of flutter speed and gust response will be used in future bridge designs.

A second unique technology developed for use on the Akashi Kaikyo Bridge was the use of parallel wire strand for cable fabrication and erection. Rather than using traditional cable-spinning methods for on-structure cable fabrication, individual parallel wire strands were fabricated off-site, transported to the bridge site, and strung parallel to each other to form the main cable. The advantage of using the new method is that the strands are continuous from anchorage to anchorage and eliminate the in-place spinning of cables, thus reducing the probability of accidents occurring. To use the parallel wire strand method, a unique cable-squeezing machine was designed to form the parallel strands into the final circular shape. The use of higher strength wires (180 kg/mm2 ) reduced the number of strands required, thus saving erection time and cost. Use of the higher strength wire also reduced (from four to two) the number of suspender ropes needed to connect each stiffening truss panel point to each cable hanger attachment on the main cable. This accounts for reduced erection time and cost savings. Performance in Earthquake Of particular interest was the performance of the bridge in the Jan.

17, 1995, Hyogo-ken Nanbu Earthquake, which provided a full-scale test of tower response. The complete bridge structure was designed to resist a 150-kilometer-distant, 8.5-Richter-magnitude earthquake. Fortunately, erection of the bridge stiffening truss had not begun. The Nojima fault zone passes between the towers of the bridge, and the earthquake caused a permanent lateral and vertical offset of the Awaji tower and anchorage. Ground fault rupture was visible on the northern tip of Awaji Island, approximately two kilometers from the Awaji anchorage. The Awaji tower was displaced 1.3 meters to the west, while the Awaji anchorage was displaced 1.4 meters to the west, relative to the Kobe tower and anchorage. This resulted in a 0.8-meter increase in span length between the main towers and a 0.3-meter increase in the southern side span length. The Awaji tower pier was displaced 0.2 meters vertically downward, while the Awaji anchorage rose by 0.2 meters. The sag in the main cable was reduced by 1.3 meters.

The earthquake caused a one-month delay in the construction schedule during which the bridge was carefully inspected for damage. This lost time was made up during the remaining three-year construction period, and the bridge was opened to traffic on schedule. The increased distance between towers was accommodated by the redesign of the two center stiffening panels, which are 0.4 meters longer than originally designed. Other minor damage was inflicted to the cable-squeezing machine, which was quickly repaired. Anchorages, piers, and towers were otherwise undamaged. Safety First The bridge was under construction for 10 years. In spite of the dangers associated with this type of construction project, elaborate safety procedures paid off. A couple of accidents resulted in six injuries and no deaths, a world-class safety record. Looking Ahead Now that the world's longest suspension bridge is in service, sights are being set on even longer spans. Preliminary plans are underway to investigate the feasibility of even longer span bridges in Japan. Japanese officials indicate that they are looking to extend main span lengths to 2,400 meters, clearly a daunting challenge for suspension bridge design in the new millennium.

The author has followed the design and construction of the Akashi Kaikyo Bridge since 1985, and he was one of only a dozen foreign officials invited to attend the opening of the bridge. He presented a congratulatory letter from Federal Highway Administrator Kenneth Wykle to the executive director of the Honshu-Shikoku Bridge Authority. James D. Cooper is chief of the Structures Division in the Office of Engineering Research and Development at the Federal Highway Administration's Turner-Fairbank Highway Research Center in McLean, Va. He received his bachelor's and master's degrees in civil engineering from Syracuse University. He is a licensed professional engineer in the District of Columbia. What is the most populated island in Japan? | Reference.com What is the most populated island in Japan? A: Quick Answer Honshu is Japan's largest and most populated island. It has 10,084 kilometers of coastline and is the world's second most populated island. Full Answer Honshu is considered to be Japan's mainland, and like the rest of the country, it is volcanic and mountainous. Mount Fuji, an active volcano, is the highest peak on the island, and Honshu's Shinano River is the largest in Japan.

The climate in the area varies greatly and ranges from subtropical in the southern areas to cool in the northern areas near Hokkaido. The largest cities on this island include the nation's capital, Tokyo, as well as Osaka and Kyoto.

Question: Which is the largest island in Japan?
Answer: HONSHU